This work rewrites such plans before submission to the relational database back-end. Once cast into the shape of join graphs, we have found off-the-shelf relational query optimizers - the B-tree indexing subsystem and join tree planner, in particular - to cope and even be autonomously capable of "reinventing" advanced processing strategies that have originally been devised specifically for the XQuery domain, e.g., XPath step reordering, axis reversal, and path stitching. Performance asssessments provide evidence that relational query engines are among the most versatile and efficient XQuery processors readily available today.